Rotary drier or cooler



P 1950 J. 1.. ERISMAN 2,522,025

ROTARY DRIER OR COOLER Filed April 9 1946 4 Sheets-Sheet l Sept. 12, 1950 J. L. ERISMAN ROTARY DRIER 0R COOLER 4 Sheets-Sheet 2 Filed April 9, 1946 Sept. 12, 1950 J. L. ERISMAN 2,522,025

ROTARY DRIER 0R COOLER Filed April 9, 1946 4 Sheets$heet 3 Sept. 1950 J. L. ERISMAN 2,522,025

ROTARY DRIER OR COOLER Filed April 9, 1946 4 Sheets-Sheet 4 tfohziflralsmam Gamma/g Patented Sept. 12, 1950 U.NITED PATENT OFFI E I ROTARY DRIER ORJCOQLER John L- Erisman, Oak Park, 111., assignor to Link- Be p we s, e ewratis!!! ll e s Application April 9, 194-6, serial No. 660,719

20 Claims. 1

This invention relates to rotary dryers or coolers of the general type disclosed in the patent to Gustav Bojner et al., No. 1,709,456, issued April 16, 1929, and deals more particularly with the features of regulating the depth of the bed of material being dried or cooled by controlling the rate of discharge of the material and exhausting the drying or cooling fluid after it has served its intended purpose.

The type of dryer or cooler covered by the above identified patent has been employed extensively in commercial installations for handling numerous types of flowable solids. As thus used, it has consisted of a rotatable, horizontally arranged cell or cylinder through the central treatment chamber of which the material to be treated, while being handled as a bed, is caused to travel lengthwise of and is gently agitated as a result of rotation of the cell or cylinder. This central treatment chamber is formed by an annularseries of longitudinally extending, circumferentially spaced louvres on the inner circumference of the cell or cylinder. The louvres collectively form a, circumferentially arranged series of longitudinal passages with each passagehaving open communication with the said central treatment chamber. By delivering hot or cold treatment fluid through a stationary inlet manifold that registers successively with the adjacent ends of only those longitudinal passages that underlie the bed of material as the cell or cylinder revolves, it will be seen that the treatment fluid will be caused to permeate radially inwardly through the material of the bed for drying or cooling the material. The material, after being properly dried or cooled, and the treatment fluid, after passing through the bed of material, are discharged from one end of the cell or cylinder.

The depth at which the bed of material must be maintained was determined by the charac- V teristics of each particular kind of material; 1. -e., its lump or grain size, the amount of drying or cooling required to properly condition the material, the retention period provided for the material, etc. g

The material was built up as a bed in the treatment chamber by damming up the discharge end of the cell or cylinder and the height, or radial dimension, of the structure employed for creating the damming action determined the depth 01 the bed. It has been the commercial practice to employ a series or set of concentric, solid rings fitted in the discharge end of the cell or cylinder to back-up or dam the material, by acting .as a weir plate over the inner edge of which the mahaustins f the used, treatment fluid.

ser al wa dischar es. Te indiv rings 91 a series or set were so constructed that they fitted on within the other an b ng ifq m red dimension, time a r n w s ed 9r moved the height or depth of the resultant weir plate and in diameter cf the c t l di ha op nin were change q al to he rem ved rins- This method o re ulatin the de t 9f the in ers y y an mu e mmens qn or t e ad d 9? bed of material maintain d i t e ment chamber of the cel or cylinder alwa ha resented sev ral diifrl ulties whic il be d sc ssed as fellows:

1. The depth of the bed of mat r a c uld be c an ed n y by certain definit steps mou each one of which was equal to the radial dimensionof one ring.

Because the positioned rin s colle ively function as .a weir p ate over the inner edge o which the materia spi led, t e m t al, that was discharg d always cam from the c ntra p n o the top la er of the bed- C nsequent- In if the material was of .cliii rent ra n. or lump s and a certainamount oi se re ion eats size resulted wi in the t eatm nt chamb r t ri tyne weirdid not .efiect c ch ge of a uniform cross section of the material in the bed;

trProbably the most serious dimculty o all was the effect the. r ms type we had on the x.-

It ha been stated above that the treatment fluid was dis harged throu h the central cheni le of the ring assembly controllin the depth f the be of material. Therefore, as the depth of the bed vwas increas d, the area at the central discha pening was decreased, The restr ctin or .0. 1- tra t ns r the new path. for he tr atm t flu d, caused by the ring as 1y, in r as d the v l ity .of th lluid at its d1 .ll rs poin and c eate additional back pressure upstream of the assemblyhis inc eased velq y of he uid caused more fine p rt cles, h ld in su pen cn the t eatmen chambe to be ca i d. o w te exhausted fluid which r s lted m l ts. 9 the ex austed mat al whi h re ui e th move .f cm th flu d b Eli added ba k pre nters a dust c lle tqr;

quired more power to be consumed in forcing the merit tighte resulti ir n the estimat n i th s treatment fluid.

It th nuimarr ob ect of this inventient provide new and novel means for regulating the depth of the bed of material maintained in the treatment chambers of horizontally rotatable dryers or coolers of the above mentioned type.

A further object of the invention is to provide means of the above mentioned type which may be adjusted so as to maintain the bed of material at any one of an infinite number-of different depths or so as to effect positive unloading of all of the material in the bed, such as when feeding of the material to the dryer or cooler has stopped for a shut-down period or when the operatorv is desirous of cleaning out the apparatus for making repairs.

Another object of the invention is to provide bed depth regulating or controlling means which:

' "ring to Figs. 1 to 3 inclusive, the reference character l0 designates the outer cell or cylinder of a horizontally arranged, rotatable dryer or cooler. The cell or cylinder is provided with a suitable number of supporting peripheral rings or tracks I I that ride on the rollers l2 suitably jourwill effect discharge of a uniform cross section of the material in the bed regardless of the depth at which the bed is maintained or regardless of whether segregation as to size is occurring in the bed.

Still another and very important object of the invention is to provide means which will effect control or regulation of the depth of the bed of material by performing a damming action, but which will not reduce to any material extent the area-of the opening at the discharge end of the treatment chamber, through which the used treatment fluid is exhausted, beyond the reduction caused by the bed'itself, with the result that the velocity of flow of the fluid-is not materially increased at its point of discharge and no substantial additional back-pressure is created by the controlling or regulating means.

Another object of theinvention is to provide means for regulating the depth of the bed of material which comprises a desired number of specially shaped vanes arranged in the discharge end of the treatment chamber and individually adjustable as to pitch to vary the extent to which each vane either holds back or dams up the material to form a bed or positively expels the material to effect complete unloading of material from the treatment chamber.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is an end elevational view of the type of rotary dryer or cooler embodying this invention,

Figure 2 is an enlarged end elevational view of the feed end of the dryer or cooler with the stationary end plate structure removed,

Figure 3 is a longitudinal, vertical sectiona view of the dryer or cooler illustrated in Figs. 1 and 2,

Figure 4 is an end elevational view of the discharge end of the dryer or cooler,

Figure 5 is a fragmentary vertical sectional view of the discharge end of the dryer or cooler naled in the supporting frame or base l3.

At the feed end of the dryer or cooler cell or cylinder Ill, a stationary distributor head or ring I 4 is positioned and is supported by the frame members l5, see Fig. 1. At this feed end, the cell or cylinder I6 is provided with a feed plate 16 having a central opening through which the material to be treated is delivered to the central treatment chamber of the dryer or cooler. The distributor head or ring I 4 is formed with a treatment fluid inlet manifold I! through which the hot or cold treatment fluid is delivered to one selected portion or zone of the interior of the cell or cylinder H3 at a point adjacent its inner circumference.

The patent to Charles A. Schneider, No. 2,253,898, issued August 19, 1941, discloses in considerably greater detail the construction of the stationary distributor head. 01' ring M and the treatment fluid inlet manifold I1. Consequently, reference may be made to this patent for a more detailed disclosure of this structure.

The dryer or cooler cell or cylinder I0 is intended to have formed therein an annular series of longitudinal passages adjacent its inner circumference. These passages, which bear the reference character '20, are disclosed in Figs. 1, 2 and 3 as being formed by the longitudinally eX- tending, radial louvre plates 2i that are secured along their outer longitudinal edges to the inner surface of the cell or cylinder 19 in any suitable manner, such as by continuous or tack welding or by being flanged and bolted or riveted to the cell or cylinder. By inspecting Fig. 3, it will be seen that the radial louvres 2| are graduall reduced in depth lengthwise of the cell or cylinder 10 with the result that the space defined collectively by the inner, free longitudinal edges of these louvres gradually increases in diameter from the feed end to the discharge end of the cell or cylinder.

Figs. 2 and 3 disclose the inner free edge portions of the radial louvres 2| as being cut away or notched at desired longitudinally spaced intervals. These notches 23, for the several radial louvres 2|, are arranged in circumferentlally aligned sets and function to receive the continuous, annular bars 2 1. These bars are welded to the adjacent portions of the radial louvres 2|.

Fig. 2 illustrates the continuous annular bars 24 as having secured to the inner surfaces thereof a desired number of transversely arranged filler bars 2-6 which are uniformly spaced circumferentially therearound. Each one of these filler bars supports in spaced relation to the inner surface of its continuous annular bar 24 a hold down bar '21 which projects circumferentially beyond its associated filler bar in a direction that is rearwardly of the direction of rotation of the cell or cylinder II D, as indicated by the direction arrow :28a of Fig. 2. These-filler bars-2:6 andhold down bars Zlcooperate withkeach other to 'fo'rm'a circumferential series of clips for each annular bar 24.

Figs. 2 and 3 disclose'an annular series of longitudinal1y extending, tangentially arranged "inner rlouvres 28 which are positioned inwardly of the radial-louvrcs-2 i Thesetangential louvres overlap each other rearwardly with reference to the direction of rotation of the cell or cylinder I'll...

Each tangential louvre28 is formed with a bent inner flange 29 that is arranged "to extend substantially radially of the cell or cylinder Ill. The outer longitudinal edge portions 'sfi of the tan.- "gential louvres 28 areb-ent at an o-btuse angle with respect tothe main'body-portions of these louvres. These last mentioned'bent end portions are provided with circumferentially aligned notches 3!. Each circumferentially alignedse riesof tangential louvre'notches 3! is intended to hayepositioned therein a continuous, annular rod 32. These rods are fastened or anchored to the tangential louvres by triangularly shaped filler pieces 33 which are welded'to both the an;- nular ring 32 and the associated tangential louvres 2B. The longitudinally spaced rings -32 function to tie together and brace'the several tangential louvres 23.

7 By inspecting Fig. 2, it

'dle bars or shoes arepositoned so as to register with the continuous, annular bars 24 which are attached to the radial louvres 2i. Triangular filler piecestii are secured to the adjacent surfaces of both the tangential louvres 28 and the saddle bars or shoes 35.

By particularly inspecting Fig. 2, it will be seen that these saddle'bars or shoes 35 function "to support the tangential louvres 28 on the continuous annular bars 24, and that the clips, that are-formed bythe filler bars "ZB'andliold down bars "llyfunction to fasten the saddle bars or shoes 35 to the continuous annular'bars 24.

By'inspecting Fig.2, itwill be seen thattwo 'tangential'louvresit are provided for each one of the longitudinal-fluid passages 'fiil. These tangentiallouvres, therefore, form tw'o outlet openings or slots for'e'ach longitudinal fluid passage 20 through which thetreatrnent fiuid delivered to "thepassages will be permitted to flow into the central treatment chamber that is collectively dezfinedby the annular series oftangential louvres 2B.

When the dryer or cooler cell or cylinder 10 is rotated in the direction of the arrow line 28a of Fig. 2, the bed of material being treated will be positioned as indicated by the dash line 38. This bed of material will be supported ioy the tangential louvres 28 that underlie the same. The spacesor gaps that are left between the outer edges of the flanges 29 and the opposite surfaces of adjacent tangential louvres 28 determine the amount of treatment fluid that can pas from the "fluid passages 20 through the outlet openings or slots that" are formed between adjacent tangential louvres. The-provision of a plurality of outlet openings or slots for each fluidpassage '29 makes it possible to-flow a substantial amount oi treatmentfiuid; at-a lowvelocity; through the bed;,of material. It/will be appreciated by inpecting Figs. 1 and 3 that the treatment fluid will be seen that the inner fi anged l'ongitudinal edge portions 29 of throat 42 rotateswith the cell or cylinder.

6 I feeding manifold l'l operates toefiTectdelivery-of the hot or cold treatment fluidonl y to the passages 20 which underlietheibed ofmaterial 38ers "of the treatment chamber were-left entirely'open,

or were entirely unobstructed throughout-its area, no su bstantial bed of-material would be provided within the treatment chamber. As it is. necessary to maintain th material in the treatment chamber at a bed depth that will prevent the treatment fiuid frcmblowing through'the'material; that is, forming blow holes inthe material, the material must be; maintained as a bed'oi'suitable depth, depending upon the particleor lump size of the material, itsangle of -repose, etc. Consequently, it is necessary to-dam uporholdback the material by som suitable structure-at the discharge end of the treatment chamber and this dammingor retarding structure must be such thatit will maintain the bedof material-at the desired depth.

Prior to the-developmentof this invention, the concentric ring type of weirplate illustrated "in Fig. 9 was employed for maintaining thebed of material at the desired depth. This material bed regulating structure of the prior art consisted of a suitable number of concentric rings-39 that were held nested one withinthe'other'iby -means of the fastening devices 40. Thesenested rings 39 acted as a weir plate over the inner edge of which the material of the bed-38 spilled.

It will be appreciated, therefore, that the deeper the bed of material that was maintained, thelarger the number of rings 39 that mustbe employed. As the treatment fluid must be discharged throughthe central opening M of the discharge weir plat structure, formed :by the rings 39, it willbe appreciated that the area of prior art type of discharge and material bed maintaining'mechanism are set forth above.

The dryer or cooler mechanis'm. embodyin'gthis invention is provided with an improved form'of discharge nozzle or mechanism that is clearly illustratedin Figs. 3 tor8 inclusive. Thisrn-echanism includes a discharge throat 42 that is hollow or of tubular formation. This throat'is suitably fastened at its inner edge to the "end ring 42a thatforms apart of the dryer or cooler cell or :cylinderlil. Consequently, thedischar'ge By inspectingFig. 4, it will'be seen that the discharge throat '42 i of'octagonal shapein'end elevation.

Although it is desirable that the discharge throat '42 be of such a shape as to provide a plurality of'fiat portions, it is to be understood that this invention is not limited to an eight-sided throat member.

One of them is illustrated in'detail in'Figs. '7 and *8. By referring to these figures, it will be seen.

that' each" vane is providedwith a base or'mountillustrates this angular relation as being in the order of 60. It is to be understood, however, that the invention is not limited to thi particular angle. By inspecting Fig. 7, it will be seen that the longitudinal side edge 46 slopes in alongitudinal direction relative to the base 45. This slope is indicated as being in the order of 45 but other angular relations can be employed. The remaining longitudinal dge of the vane is illustrated as being formed with an inner portion 4! and an outer or major portion 48. The outer portion is illustrated in Fig. 7 as being arranged at an angle of 28 with respect to the base flange 41. It is to be understood, however, that other angular relations can be employed. The difference in the angular slope of the edges 46 and 48 will be explained at a later point.

By considering Figs. 3 to 6 inclusive, it will be seen that each one of the vanes 44 is attached to a flat side portion 43 of the discharge throat 42 by means of a bolt and nut 49. This type of fastening means is employed when it is desired to be able to adjust the vanes relative to their bases 43. That is to say, the vanes 44 can be adjusted about the axes of their fastening devices 49 if so desired. Under certain operating conditions, it may be desirable to permanently, or non-adjustably, fasten the vanes 44 to their flat base portions 43 of the discharge throat 42. When that is the case, the base flanges 45 of the vanes 44 may be welded to the discharge throat 42.

By inspecting Fig. 4, it will be seen that the vanes 44 are so mounted on the inner circumference of the discharge throat 42 that they are inclined rearwardly with reference to the direction of rotation that is represented by the arrow line 28a. This rearward inclination is brought about by the angular relationship between the base flange 45 and the main body portion of each vane. Fig. 3 best illustrates the vanes 44 as being attached to the discharge throat in such a manner that their longitudinal sloping edges 46 are presented to the interior of the treatrnent chamber of the cell or cylinder l while the remaining sloping edges 48 are presented to the outlet end of the throat 42. Figs. 3 to 6 inclusive illustrate the various vanes as being arranged so as to have a pitch or transverse inclination axially of the discharge throat 42 and the cell or cylinder l0. Figs. and 6 are intended to illustrate pitches of 45 and respectively. It will be appreciated that the adjustable type of mounting provided by the fastening devices 49 permits the vanes to be adjusted independently and at any desired pitch angle. Figs. 3 to 6 inclusive illustrate what will be termed positive pitch angles of adjustment. That is so say, the outer sides or edges of the vanes are positioned in advance of the inner sides or edges of the vanes with reference to the direction of rotation represented by the arrow line 28a. These positive pitch angles will cause the vanes to produce a damming or holding back action with reference to the material moving through the treatment chamber. The vanes can be adjusted so as to provide what will be termed a zero pitch angle. When thus arranged; the faces of the vanes will be arranged in parallel- .ism to the axis of the discharge throat 42. When thus arranged, the vanes will not function to dam up or hold back the material to any material extent. The vanes, also, can be adjusted so as to have what will be termed a negative pitch. When thus arranged, their inner edges 46 will be positioned in advance of their outer edges 8 48 with reference to the direction of rotation represented by the arrow line 28a. When the vanes have a negative pitch, they will function to positively effect discharge of the material from the bed 38.

From the above explanation, it will be appreciated that each one of the vanes 44 may be independently adjusted so as to have any desired positive pitch, any desired negative pitch, or zero pitch. Consequently, all of the vanes may be provided with positive pitches so as to function to retard the flow of material through the discharge throat and thereby hold back the material to form a bed within the treatment chamber of the cell or cylinder. Also, the positive pitches of the several vanes may be the same or may differ from each other to any extent desired. It will be appreciated that the depth of the bed of material that should be maintained within the treatment chamber of the cell or cylinder [0 depends on the characteristics of the material. Therefore, the vanes 44 can be set at any desired combination of positive pitch angles to so regulate the rate of discharge of the material through the throat 42 that the desired bed depth will be maintained. It, further, will be appreciated that when the operator of a dryer or cooler, equipped with this type of discharge mechanism, desires to completely unload or empty the material of the bed, one or more of the vanes 44 may be adjusted so as to provide a negative pitch angle. When thus arranged, the vane or vanes will not function to dam up or hold back the material as they move across the discharge end of the bed 38. Therefore, continued rotation of the cell or cylinder II] will cause the vane or vanes having negative pitch angles of adjustment to function to completely unload or empty the material from the treatment chamber of the cell or cylinder.

The manner in which the vanes 44 function to dam up or hold back the material to form a bed, and the manner in which the vanes function to effect discharge of the desired amount of bed material is so peculiar and unusual that it is practically impossible to illustrate or accurately describe the same. Figs. 5 and 6 represent attempts at disclosing the difference in the damming or holding back actions of the vanes when arranged at two positive pitch angles. It will be seen that the pitch angle of 45 illustrated in Fig. 5 will maintain a bed of greater depth than will the pitch angle of 20 of Fig. 6.

By considering the disclosure of Fig. 4, the direction of rotation represented by the arrow line 28a. will cause the vanes 44 to move first downwardly into the lower edge portion of the bed 38, or into the edge portion indicated by the reference character a. If there is any segregation of the material as to grain or lump size, the larger grains or lumps will be found in this portion of the bed. The material from the lower edge portion a of the bed will first flow into the space or opening provided between the vane advancing into the bed at this point and the vane that next precedes it.

As each vane progresses across the discharge face of the bed of material 38, a different portion of the bed flows into the opening provided in advance of each vane. This flow of material into these openings continues until the vanes rise above the upper edge portion b of thebed. Depending upon the angle of repose of the material forming the bed 38 and the positive pitch angle at which the vanes are set, different portions of 11 around the inner circumference of said throat, each one of said vanes being longitudinally inclined rearwardly relative to the direction of rotation of the cylinder and transversely inclined in the direction of the axis of the throat to control the rate of discharge of material from the bed through the throat, and means for adjusting the transverse inclination of any desired number of vanes for changing the depth of the bed.

7. A discharge device for a rotatably supported, horizontally arranged cylinder through which a bed of material is continuously advanced while being dried or cooled by treatment fluid permeating upwardly through the bed, comprising a tubular throat through which the material from the bed is discharged, and a plurality of vanes spaced around the inner circumference of said throat, each one of said vanes being longitudinally inclined rearwardly relative to the direction of rotation of the cylinder, transversely inclined relative to the axis of the throat, and having its side edges sloping toward the outlet end of the throat to control the rate of discharge of the material therethrough and thereby regulate the depth at which the bed is maintained.

8. A discharge device for a rotatably supported, horizontally arranged cylinder through which a bed of material is continuously advanced while being dried or cooled by treatment fluid permeating upwardly through the bed, comprising a tubular throat through which the material from the bed is discharged, a plurality of vanes spaced around the inner circumference of said throat, each one v of said vanes being longitudinally inclined rearwardly relative to the direction of rotation of the cylinder, transversely inclined relativeto the axis of the throat, and having its side edges sloping toward the outlet end of the throat to control the rate of discharge of the material,

therethrough and thereby regulate the depth at which the bed is maintained, and means for adjus'ting the transverse inclination of any desired number of the vanes for changing the depth of the bed.

9. A' discharge device for a rotatably supported, horizontally arranged cylinder through which a bed of material is continuously advanced while being dried or cooled by treatment fluid permeating upwardly through the bed, comprising a tubular throat through which the material from the bed is discharged, and a plurality of vanes spaced around the inner circumference of said throat, certain of said vanes being transversely inclined relative to the axis of the throat with their trailing edges arranged inwardly to hold back the discharge of material to form a bed while the remainder of the vanes are transversely inclined relative to the axis of the throat with their trailing edges arranged outwardly to effect positive discharge of the material from the bed at a desired rate.

10. A discharge device for a rotatably supported, horizontally arranged cylinder through which a bed of material is continuously advanced while being dried or cooled by treatment fluid permeating upwardly through the bed, comprising a tubular throat through which the material from the bed is discharged, a plurality of vanes spaced around the inner circumference of said throat, certain of said vanes being transversely inclined relative to the axis of the throat and with their trailing edges arranged inwardly to hold back the material to form a bed while the remainder of the vanes are transversely inclined relative to the axis of the throat and with their:

trailing edges arranged outwardly to efiect positive discharge of the material from the bed at a desired rate, and means for independently adjusting the transverse inclination of each one of the vanes.

11. A discharge device for rotary horizontal dryers or coolers for flowable solids, comprising a rotatable tubular throat through which the material from the dryer or cooler is discharged, and material damming means positioned in the bore of said throat for controlling the rate of discharge of the material from the throat, said material damming means presenting to the material to be discharged an annular series of circumferentially spaced surfaces, each one of said surfaces being inclined both relative to the direction of rotation of and relative to the axis of the throat.

12. A discharge device for rotary horizontal dryers or coolers for flowable solids, comprising a rotatable tubular throat through which the material from the dryer or cooler is discharged, and a plurality of material damming vanes spaced around the inner circumference of said throat to control the rate of discharge of the material from the throat and thereby regulate the depth at which the bed is maintained, each of said vanes being longitudinally inclined rearwardly relative to the direction of rotation of the tubular throat and having one of its longitudinal edges trailing the other longitudinal edge during such rotation.

13. In a device of the type described, in combination a rotatably supported, horizontally ar-- ranged cylinder, means forming a central treatment chamber in said cylinder to receive and advance the material to be treated, means for delivering material to the feed end of said chamber, a circumferentially arranged series of longitudinal passages surrounding and in open communication with the central treatment chamber, means for supplying treatment fluid to said passages for delivery to the bottom portion of said chamber, and material damming vanes positioned at the discharge end of the treatment chamber for controlling the rate of discharge of the material from the chamber and thereby forming the material into a bed of desired depth in the bottom portion of the chamber, each of said vanes 50 presenting to the material of the bed a substantially flat surface that is inclined both relative to the direction of rotation of and relative to the axis of the cylinder.

14. In a device of the type described, in com- 55 bination a rotatably supported, horizontally arranged cylinder, means forming a central treatment chamber in the cylinder to receive and advance the material to be treated, means for delivering material to the feed end of said cham- 60 ber, a circumferentially arranged series of longitudinal passages surrounding and in open communication with said central treatment chamber, means for supplying treatment fluid to said passages for delivery to the bottom portion of- 13 ment chamber in said cylinder to receive and advance the material to be treated, means for delivering material to the feed end of the chamher, a circumferentially arranged series of longitudinal passages surrounding and in open communication with the central treatment chamber,

means for supplying treatment fluid to said passages for delivery to the bottom portion of said chamber, and a plurality of circumferentially spaced material damming vanes positioned at the discharge end of the treatment chamber for rotation therewith and transversely inclined relative to the axis of the treatment chamber for controlling the rate of discharge of the material to form the material in the chamber into a bed of desired depth.

16. In a device of the type described, in com bination a rotatably supported, horizontally arranged cylinder, means forming a central treatment chamber in said cylinder to receive and advance the material to be treated, means for delivering material to the feed end of the chamber, a circumferentially arranged series of longitudinal passages surrounding and in open communication with the central treatment chamber, means for supplying treatment fluid to said passages for delivery to the bottom portion of said chamber, a plurality of circumferentially spaced material damming vanes positioned at the discharge end of the treatment chamber and inclined outwardly relative to the direction of movement of the material in discharging for retarding the discharge of the material to form the material in the chamber into a bed of desired depth, and means for adjusting the angle of inclination of any desired number of said vanes for changing the depth of the bed.

17. In a device of the type described, in combination a rotatably supported, horizontally arranged cylinder, means forming a central treatment chamber in said cylinder to receive and advance thematerial to be treated, means for delivering material to the feed end of the chamber, a circumferentially' arranged series of longitudinal passages surrounding and in open communciation with the central treatment chamber, means for supplying treatment fluid to said passages for delivery to the bottom portion of said chamber, and a plurality of circumferentially spaced material damming vanes positioned at the discharge end of the treatment chamber, each one of said vanes being longitudinally inclined rearwardly relative to the direction of rotation of the cylinder and being transversely inclined relative to the axis of the cylinder to control the rate of discharge of the material from the chamber and thereby forming the material in the chamber into a bed of desired depth.

18. In a device of the type described, in combination a rotatably supported, horizontally arranged cylinder, means forming a central treatment chamber in said cylinder to receive and advance the material to be treated, means for delivering material to the feed end of the chamber, a circumferentially arranged series of longitudinal passages surrounding and in open communication with the central treatment chamber, means for supplying treatment fluid to said passages for delivery to the bottom portion of said chamber, a plurality of circumferentially spaced material damming vanes positioned at the discharge end of the treatment chamber, each one of said vanes being longitudinally inclined rearwardly relative to the direction of rotation of the cylinder and transversely inclined relative to the axis of the cylinder to control the rate of discharge of the material from the chamber and thereby form the material into a bed of desired depth in the bottom portion of the chamber, and means for adjusting the transverse inclination of any desired number of the vanes for changing the depth of the bed.

19. In a discharge device, the combination with a rotatably supported, horizontally arranged cylinder having a central treatment chamber through which material is continuously advanced While being dried or cooled by treatment fluid permeating radially through the material, of a tubular throat, through which the material from the chamber must discharge, mounted on the discharge end of the cylinder to rotate therewith and having a bore in open cormnunication with and of substantially the same diameter as that of the discharge end of said central treatment chamber, and a plurality of circumferentially spaced material damming vanes mounted in the bore of said throat for rotation therewith and positioned for controlling the rate of discharge of material from the treatment chamber through said throat to thereby form the material into a bed of desired depth in the bottom portion of the chamber.

20. In a discharge device, the combination with a rotatably supported, horizontally arranged cylinder having a central treatment chamber through which material is continuously advanced while being dried or cooled by treatment fluid permeating radially through the material, of a tubular throat, through which the material from the chamber must discharge, mounted on the discharge end of the cylinder to rotate therewith and having a bore in open communication with and of substantially the same diameter as that of the discharge end of the said central treatment chamber, a plurality of circumferentially spaced material damming vanes mounted in the bore of said throat for rotation therewith and positioned for controlling the rate of discharge of material from the treatment chamber through said throat to thereby form the material into a bed of desired depth in the bottom portion of the chamber, and means for fastening each vane to the throat for independent adjustment to vary its control over the rate of discharge of the material by changing its transverse inclination in the direction of the axis of the throat.

JOHN L. ERISMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 303,915 Breer Aug. 19, 1884 633,791 Burnett Sept. 26, 1899 1,617,815 Lissauer et a1 Feb. 15, 1927 1,703,635 Ranson Feb. 26, 1929 2,095,086 Slemmer Oct. 5, 1937 2,213,713 Maxson Sept. 3, 1940 2,290,765 Overman July 21, 1942 2,309,810 West Feb' 2 1943 OTHER REFERENCES The Link-Belt Roto-Louvre Dryer, Book No. 1911, Link Belt Company. 

